The type of blasting grit must be selected based on the application. Aluminum oxide is a common blasting abrasive used for surface preparation prior to painting or other finishing processes. Crushed glass is used when aggressive material removal is required. Glass beads are used for smooth, cosmetic finishes.
Silicon carbide is the hardest blast media and as such has a very fast cutting speed. Due to its high durability, it can be reused several times. Organic materials, such as corn cob and walnut shell, are used for applications that require surface cleaning with limited material removal.
Each blast media comes in a number of grit sizes, which must be selected based on the desired finish. Larger grits generally produce a rougher surface, while fine grits produce a smooth surface.